The expression is given in reverse polish notation .it means that is in post order.
Reverse polish notation => post order traversal
Make a expression tree for above post order expression is
From above expression tree NEW ORDER TRAVERSAL is 11 17 16 * + 12 15 14 13 * - ^ –
( Above new traversal strategy is called CONVERSE POSTORDER . )
If give traverse ROOT , RIGHT , LEFT => called CONVERSE PREORDER
If give traverse RIGHT, LEFT, ROOT => called CONVERSE POSTORDER